Power operated pipe wrench



ug. 30, 1960 J. c. MASON POWER OPERATED PIPE WRENCH 3 Sheets-Sheet lFiled Aug. 11, 1958 NS S nl.. il

Aug. 30, 1960 J. c. MASON POWER OPERATED PIPE WRENCH 3 Sheets-Sheer. 2

Filed Aug. ll, 1958 Maz 6.

INVENTOR.

BY faul-Mlm C, g-WIL- Aug- 30, 1960 J. c. MASON 2,950,639

POWER OPERATED PIPE WRENCH Filed Aug. 11, 1958 Y 5 Sheets-Sheet 3 @MES@I Manso/Vy IN V EN TOR.

PWER PERATED PIPE WRENCH James C. Mason, Long Beach, Calif., assigner toM ason- Carlton Tool Co., Paramount, Calif., a corporation rned Aug. 11,195s, ser. No. 754,237

10 claims. (c1. rs1-53) The present invention relates generally to' oilfield equipment, and more particularly to an improved powerdriven pipetong. This application is contlnuation-inpart of co-pending applicationtiled June 24, 1954, under Serial No. 439,061 for `a Power-Driven PowerOperated Pipe Wrench, which issued August 12, 1958, under Patent No.2,846,909.

Power-driven pipe tongs are widely employed in oil well drilling and theproduction of oil. These tongs `are particularly adapted for use inrapidly screwing and unscrewing the threaded ends of strings of casing,drill pipe .and tubing utilized in the bore hold of an oil well, in thatthey permit considerable saving of time and money.

Additionally, these power tongs are far safer in actual use thanconventional pipe tongs previously available, for they arepower-operated and substantially eliminate the manual labor and physicalhazards heretofore encountered in running a string of casing, drillpipe, or tubing into a well bore or in removing the same therefrom.

A major object of the present invention is to provide an improved powertong by means of which a more eiicient and versatile transmission ofpower from the prime mover to the pipe-engaging elements thereof iselected, which rotatably and adjustably supports the pipe-engagingelements in a manner to compensate for wear thereof as well as tominimize transmission of sudden shock thereto when the dies assume apipe-engaging position, and `allows for selective variation in thelatching -force to that required for a particular job.

Another object of the present invention is to provide an improved powertong that is more compact, lighter in weight, simpler in construction,and more versatile in operation than the tong disclosed in my previouslymentioned Patent No. 2,846,909.

These and other objects and advantages of the present invention over thedevice disclosed in my previously mentioned Patent No. 2,846,909, willbecome apparent from the Ifollowing description of a preferredembodiment thereof, and from the accompanying drawings, wherein:

Figure l is a side elevational view of the improved power tong of thepresent invention;

Figure 2 is a top plan view of the tong shown in Figure l, taken on line2 2 thereof;

Figure 3 is a fragmentary vertical cross-sectional view of thetransmission gear train and reversible iiuid motor forming .a part ofthe invention, .taken on line 3-3 of Figure 2;

Figure 4 is a fragmentary vertical cross-sectional view of one of thepairs of rollers which rotatably support the half rings on which the diecarriers are mounted, taken on line 4 4 of Figure 2;

Figure 5 is a top plan view of one of the adjustable roller supportindexing plates, taken on line 5-5 of Figure 4;

Figure 6 is a fragmentary, vertical cross-sectional view hired ratesPatent i 2,950,639 Patented Aug. 30, 1960 ICC of a portion of thetransmission land, manually operated gear shift taken on line 6-6 ofFigure 2;

Figure 7 is a fragmentary top plan view of a frame member and jaw member`adapted to be held in rigid ,abutment -by the power-actuated latch .asshown, with portions of the frame and jaw being broken away to discloseportions of the half rings, die carrier and dies, and the manner inwhich they are supported on the frame and jaw by the rollers shown inFigures 4 .and 5;

IFigure 8 is a fragmentary elevational View of the latch in a positionto maintain the frame and jaw in the closed position of Figure 7;

Figure 9 is a fragmentary horizontal cross-sectional view of thepower-operated cam and cam-engageable member shown in Figure 7; and

Figure l0 is an exploded perspective view of a half ring, die carrierand die block.

With `further reference to the `drawings for the general arrangement ofthe invention, and particularly Figures l and 2 thereof, it will be seento include a frame member F which pivotally supports a jaw I that isadapted to be secured in a closed position relative thereto by means of`a power-operated latch L. Frame member F and jaw l are so constructedas to define a circular pipereceiving opening O in which a tubularmember P can be inserted or from which it may be removed when jaw l isin an open position relative to frame member F.

It will be understood that member P may comprise either casing, drillpipe, or tubing normally inserted in the bore hole of an oil well. Framemember F and jaw l, as can best be seen in Figures 3, 4, and 6, are ofhollow construction. Two identical semi-circular half rings B areprovided, one of which is shown in Figure l0. These half rings arerotatably supported within the confines of frame member F and jaw I,respectively, to encircle opening O (Figures 3 and 7).

Two identical semi-circular die carriers C are also provided, one ofwhich is shown in Figure l0 and partially in Figure 3. Carriers Csupport a number of circumferentially spaced die blocks D, and in turncarriers C are supported by half rings B. The outermost end surfaces ofblocks D relative to tubular member P are of curved convexconfiguration, vand these curved ends slidably engage cam surfacesformed, or otherwise provided, on half rings B.

When half rings B are rotated relative to carriers C, the die lblocks Dare moved radially inward to engage the exterior surface of tubularmember P and rotate the same. A uid actuated motor H is mounted on theupper surface of frame member F (Figure l) and is connected by means ofa conduit U to a source of uid under pressure (not shown). A firstmanually operable valve K directs fluid under pressure from conduit U tomotor H and selectively actuates the same in either of .two possibledirections for reasons to be hereinafter explained. A second valve Gselectively directs uid from conduit U to a hydraulic cylinder V, asbest seen in 'Figure 2, which cylinder actuates latch L to maintainframe F and jaw I in the closed position or release them therefrom.

Motor H drives a `gear train T (Figures 2 and 3) to rotate half rings B.By means of the manually operable `gear shift N shown in Figure 6, `geartrain T can be caused to rotate half rings B at either high speed, lowtorque, or high or low speed, high torque. A support Q for the inventionabove described is shown in Figure 1, which maintains frame member tFand jaw J in a desired horizontal position relative to the tubularmember P being rotated. A handle R 4is mounted on jaw I (Figures l and2), by means of which the jaw may be pivoted outwardly away from theforward extremity of frame member F when latch L is manually pivoted outof en- Ycenters `of pockets 58.

F andfjaw J whereby Vthey may be moved toward or away from half rings B,for reasons to be explained heretinafter.' Frame member F (Figures l, 2and 3) includes a bottom'wall 28, a side wall 30, and a top wall orVcover 32, the edges of which walls' are integrally joined. Y Rollers X,as may be seen in Figure 4, are preferably of the ball or roller bearingtype and mounted in pairs on shafts 33. Theend Vportions of each shaftare disposed in longitudinally extending, olf-centered bores 34 formedinbosses 35 that are normally disposed and Vvrigidly affixed relativetoindexing plates 36. The

end portions ,of shafts 33 are aliixed .to at least one of the bosses 35in which they are disposed by means of a pin 33a, or other fasteningmeans. Should it be desired, commercially available stock bolts can beused in place of shafts 33 as shown in Figure 4.Y Pairs of verticallyaligned openings 37 are formed in frame F and jaw I which arecircumferentially spaced around opening O, aud-one of the bosses 35 isrotatably disposed in each opening 37. Y

A plurality of circumferentially spaced bores 35 are formed inleachindexing plate 36 through which bores screws 39 extend to engage anumber of tapped bores formed in frame F and jaw J around openings 37.Rotation of indexing plates 36 moves shaft 33 and rollers X toward oraway from half rings B whereby the pressure contact between the' rollersand half rings can be controlled. Movement of rollers X'toward halfrings B by rotation of indexing plates 36 is also highly desirable inorder to compensate forwear on the half rings after prolonged use.Engagement of screws 39 with aligned bores 38 and tapped bores 40rigidly maintains shafts 33 and rollers X at the desired'positionrelative to half rings B. One-half of a ring gear 41 is aiixed'to thecentral exterior surface of each half ring B (Figure l0), vand this gearmaintains rollers X in the spaced relationship shown in Figure 3. Y

The rear portion of jaw J is pivotally secured to frame member F by avertical pivot pin 42. structurally, Yjaw I is generallyV similar tothe'front portion of frame F, and has simiiar bottom, side and topwalls. Rollers X may be adjustably supported in jaw J by the same typeof mounting assemblies employed with jaw I, as shown inV detail inFigure 4. f Y

Each half Yring B includes a vertical wall 48 from which lowerY` andupper lianges 50 and 52 respectively,

project radially inward. Ring gearr41 can Ybe either Y rigidly amxed to,or formed as an integralY part of half ring B. The exterior surfaces ofwalls yi8V are `in rolling contact with rollers X, as may be seen inFigure 7. A

i number of circumferentially spaced Wedging members 56 Y are formed onthe interior` surfacesY of walls 48,7 and each wall defines aWedge-shaped pocket 58 which receives an end portion of one of the dieblocks D. Arcuate grooves 60 .are Vformed in the upper anges 52 thatslidably receive and rotatably engage track A (Figure 3). Upper Ypipe-engaging dies Y, preferably formed with a serrated or otherwiseroughened exterior pipe-engaging face. Dies Y are fabricated froma hard,tough` material that is resistant to abrasion and are of such transversecross section as to be slidably insertable or removable in slots S3.Dies Y are rigidly maintained within the connues of slots 82 by means ofscrews, or other Vconventional means (not shown). Y.

Referring to Figures 3 and 7, it will be seen that engagement of ringgear 41 witha toothed driving roller S8 causes half rings B to Yrotaterelative to frame element F and jaw I when they are in the closedposition. Driving roller 88 is rigidly mounted on a rst shaft 90 that isrotatably supported by two vertically spaced bearings 91and 92. Bearing91'is mounted on wall 23 of frame F and bearing 92 on a bracket 93aflxed to wall 28 that projects upwardly therefrom land is situatedwithin the confines of the-frame.V

A driven rollerr88a is also rigidly affixed to rst shaft 90 and at alltimes engages a rst pinion 94 which is rigidly mounted on a secondvertical shaft 9S, the end portions of which are rotatably mounted in apairof Ybearings 95a supported by frame F. A second pinion p 96,considerably larger in diameter than pinion 94, is

also rigidly aixed to shaft' 95, above pinion 94.

A third shaft 97 that is lparallel to second shaft 95 is rotatablysupported by a pair of bearings 97a from frame F. The gear shiftmechanism N, -as best seen in Figure 6, permits selective rotation 'ofdie blocks D Vat low speed, high torque, or highv speed, low torque.Splines 98 are formed on shaft 97 that slidably engage keyways 99provided in an upper-gear 100 and a lower gear 102. Gears 100 and 102are slidably supported on shaft 97, but rotate'concurrently therewith.Gear 100 is considerably smaller in diameter than Ygear 102, and anintermediate- Vly disposed tubular member 104 having yacircumferential-Y ly extending lgroove 105 :formed thereinrigidlyconnects and lower'anges 52gand 50 also have Ia-number of pairs YVof vertically aligned slots y62 and 63 respectively, formed therein,the centersrof which are in alignment with the Y Die carriers C arepositioned between the lower and upper ilanges 50 and 52, as Vshown inFigures 2, 3 and 7 Eaclrcarrier C is formed with a number of generallyreotangulanradially extending openings 64 adapted to be Y aligned-,Withthe wedging member Vpockets 58. Verticallyalignedrbores 66 and 6,8.areformed in each die carrier ,f C that communicate with openings 64.Lightening holes Vmay also be formed in each half ring B, as shown rinFigure 10; Y

these gears. 4 Y

A rigid ring-shaped Vmember 106 is slidably supported ingroove 105, andtwo pins 107 Vproject outwardly from opposite sides thereof. AYbifurcatedV member 108 engages pins 107 that is in turn pivotallyconnected to one 'rend of a Vgenerally horizontal level-109 whichterminates in an upwardly Yextending handle 1710 that projects throughan opening 111 formed'jin frame cover 32.V Lever 109 is pivotallymounted on a horizontal shaft 112 affixed to 'theupper end portions oftwo Vlaterally separated arms 1013 which projectupwardly intdframe Ffrom wall 28 thereof. Y Y Y Y Y vA fourth verticalshaft 114 isIrotatably supported by a pair ofbearings'llia mounted onwalls 32 and2S, as shown in Figure 3. A'lower toothed member Y115 and *upper toothedmemberA llsomewhat'larger inV diameter are rigidly aXed-to shaft114.Member 116 is at all times in4V engagement with a driving gear 117mounted on a verticalV drive shaft 118 that extends upwardly to Yiluilactuated motor TheT lower end of shaft 118 is journalled in a bearingV11,9 that isrsupportedon wall 2S.'

Manual manipulation of handle Y110 moves lever 109V and bifurcatedmember 108 to place gears 100 and V102 intherst Vpositionrshown inFigure 3 where Vgea-r 102 ,engages first' pinion 94 and' -toothed member11S. Gears 'and 102 can also be moved by use of gear shift N to a secondposition in which 'gear' 100 engages second pinion' 96; while gear 102'remains in' Vengagemerrt with toothed. member 115, but out ofengagement with first pinion 94. Gear shift N also permits gears 100 and102 to be moved to a third, or neutral position, wherein gear 100 doesnot engage any toothed member, and gear 102 is in engagement withtoothed member 115 but out of engagement with first pinion 94. Thus, bymanipulation of handle 110, the gear shift mechanism N causes motor H torotate half rings B, die carriers C, and die blocks D at either highspeed, low torque, or low speed, high torque.

The support Q (Figure 1) includes a rigid bar 130 that is bent, orotherwise formed, to `denne a first downwardly extending leg 132 that ispivotally connectedv on the lower end portion thereof by a pin 134 to alug 136 which projects upwardly from frame F. Bar 130 also delines asecond upwardly extending leg 138 that is angularly positioned relativeto leg 132. The upper extremity of leg 138 terminates in an eye 146,which by means of a cable 142 aixed thereto, supports the tong from aconvenient portion of the derrick structure (not shown). A manuallyadjustable turnbuckle 144 is pivotally connected to the upper portion ofleg 138, and to a suitable fastener 146 affixed to top wall 32 aconsiderable distance inwardly from lug 136. By manipulation ofturnbuckle 144, frame F and jaw I may be pivoted relative to support Qto place the tong in a true horizontal plane. The rear end of frame Fterminates in a heavy, horizontally positioned lug 147 in which avertical bore is formed that receives a pin 148 and pivotally supportsan eye-defining member G. A dead line 152 is connected to member 150 anda portion of the derrick (not shown) to restrain rotation of the tongduring a pipe screwing operation.

. Conduit U conducts uid from a source under pressure (not shown) totirst valve K, and upon manipulation of a handle 158 provided on thevalve, uid can be discharged into the motor to cause selective rotationthereof in either of two possible directions. After actuation or motorH, fluid is directed back to its source through a second conduit Z forrecirculation through conduit U.

In detail, conduit U (Figures l and 2) includes a T connection 161) fromwhich a tubular lateral 162 extends to the inlet side of motor H, and anextension 164 of conduit U continues from T 160 to the inlet side ofsecond valve G.

Valve G, by means of a control handle 165 associated therewith, iscapable of discharging fluid through either of two conduits 166 or 168extending to opposite ends of the hydraulic cylinder V. When handle 165is placed in a first position, fluid is'discharged through conduit 166to enter cylinder V and move a piston 172 disposed therein to the left,as shown in Figure. 2. Fluid on the side of piston 172 opposite thatcontacted by the incoming iiuid is discharged through conduit 168 toreturn to second valve G. Fluid so returning to second Valve G isdischarged therefrom through a conduit 174, which by conventional means,is connected to conduit Z and returned to its source for recirculation.When handle 165 is placed in a second position, liuid entering the valvefrom conduit U is discharged from the valve to conduit extension 168 toenter cylinder 170 and force piston 172 to the right (Figure 2) with theuid on the side of the pistons communicating with conduit 166 beingdischarged therethrough to return to valve G and thereafter dischargedthrough conduit 174 to conduit Z.

, Piston 172 has a piston rod 176 aixed thereto, which extends forwardlyto a position above the latch mechanism L. The end of cylinder Vopposite that from which Vpiston rod 176 projects is pivotally connectedby a pin 177 to jaw l. Latch mechanism L includes twohorizontal,'vertically spaced supporting plates 178 and 178 'which are-welded or otherwise affixed to the forwardly disposed, verticallyextending side walls of jaw I, as best seen in Figures 2, 7 and 8. Aheavy vertical shaft 180 6 is journaled in vertically aligned,longitudinally extending slots 181, 181' formed in plates 178, 178'respectively, and an outwardly projecting arm 182 is rigidly atiixed toshaft 180. The outer extremity of arm 182 is pivotally connected by apin 184 to the outer extremity of the piston rod 174.

An intermediately positioned cam or eccentric 186 is rigidly affixed toshaft 188 by conventional fastening means. When shaft is rotated in acounter clockwise direction (Figures 7 and 9), cam 186 is brought intorotatable sliding contact with a heavy rigid camengageable member 188that projects outwardly from jaw I. This rotatable contact between cam186 and member 188 forces shaft 180 to the right in slots 181, 181'.

Latch mechanism L lalso includes an engaging member 196 and anengageable member 191. Member 190 comprises two parallel, laterallyspaced legs 194, 194 that are connected by a web 196 extending betweenthe end portions thereof, as best seen in Figure 8. Two aligned bores198, 198' are formed in the end portions of legs 194, 194 opposite thosejoined by web 196, and these bores rotatably engage shaft 180. Withengaging member 196 supported as described above, an end portion of leg194 is disposed between the lower face of plate 17S land upper face ofcam 186, and an end portion of leg 194 is located between the lower faceof cam 186 and the upper face of plate 178".

Engageable member 188 preferably includes a vertical plate 208, theinner edge of which is welded or otherwise affixed to the forwardportion of jaw side Wall 30. To strengthen plate 200 against stress andstrain, it is preferably reinforced by two parallel vertically spacedribs 202 that are rigidly affixed to wall 30. Two set screws 204 arethreaded into tapped bores formed vin web 196, and the end portionsthereof are capable of being adjusted to a desired distance inwardlyfrom web 196. A handle W is mounted on the latch engaging member 190that permits pivotal movement of the engaging member to a position whereit may be placed in engagement with engageable member 191 (Figure 7), orto a position where it is out of engagement therewith, whereby jaw l maybe swung away from frame F, which is necessary when pipe P is placed inor removed from opening O. The further the set screws 204 project to theright from web 196 Ias` seen in Figure 7, the less movement the pistonrod 176 will be required to make to bring the ends of the set screws204'into pressure contact with a at face 191e of engageable member 191.

The use of the invention is extremely simple. When it is desired toplace a tubular member P within the confines of opening O, the latch Lis disengaged and handle R is employed to swing j aw I outwardly awayfrom frame member F. The tubular member to be screwed or unscrefwed froma corresponding section thereof is placed inside frame member IF and jawI and the jaw then swung toward member F by means of handle R untilVlatch L can be placed in an engaging position. Initial engagement oflatch L brings the free ends of jaw I and frame member F intojuxtaposition, Ibut not in abutment. Likewise, when latch L is in anengaging position, the half rings B are supported by rollers X, as canbest be seen in Figure 4, but without these rollers exerting anysubstantial radial force on the outer surface of wall 48 thereof. Afterinitial pressure contact of set screws 204 with face 191er is effectedas show-n in Figure 7, the handle 165 of second valve G is manipulatedto cause fluid ow to the hydraulic cylinder V, with resultant movementof piston 172, piston rod 176, arm 182 and rotation of cam 186 toslidably contact cam plate 200, whereby jaw J and frame member F `aredrawn together and the ends thereof are placed in pressure abutment. Asjaw I and frame member F are so drawn together, due to previousadjustment of the indexing plates 36, rollers X are so radially disposedrelative to half rings B that the rollers X preso 7` o sure contacttheexteor surface of the half ring walls 48, as can .best `be seen inFigure j4. The magnitude of the force exerted b y rollers AXeinthismanner is dependent uponY the -positioning of the roller-supportingshafts 33, as well as the magnitude of the fluid `pressure beingsupplied to the apparatus through conduit U. Y First valve K is thenmanually manipulated to cause rotation 'of driving' gear 117 andresultant rotation of half rings B, die carries C, and dies D. YPrior-to rotation, diesY DY moveY radially inward as'previouslyVexplained, to engage tubular member P and thereafter cause rotationthereof. Y Y Y I The magnitude of the' torque provided by rotation ofdies D can -be controlled by the gear shift N shown in i Figure 6.; Whenhandle :110 of the gear shift is manipulatedr'to place gear 102 inmeshing engagement with 'rst pinion 94'iandlower toothed member 1157 thedies D are rotated at "high speed and low torque. However, by movementof handle 110, gears 100 and 162 can be raised to a second positionwhere gear 169 meshes'with second pinion 96 and` gear 102 remains inmeshed engagement with the lower toothed member, but is out ofengagement with first pinion 94. 'Handle 110 can also'be used inVvertically placing gears 100 and 102 in a third and neutralpositign inwhich gear 109 is entirely disengaged and gear 102 is only in engagementYwithlower toothed member 1i15.' Y Y Y The present invention, .as can4be seen from the foregoing descn'ption thereof, operates in much thesame manner aslmy invention disclosed Iand claimed in my United, StatesLetters Patent No. 2,846,909, entitled Power Driven Pipe Tong, thatissued August 12, 1958. However, the locking mechanism of the previousdevice for interlocking the half rings together has beenY dispensed withVwhereby the annoyance andY inconvenience of having'to periodicallyreplace the locking mechanism by use 'ofthe power-operated latch isavoided. In the present invention-the power-operated latch has aninitial makeup in vwhich the frame and jaw are not completely closed,but are Velo-sed by actuation of hydraulicvcylinder Vio powermove'therjaw and frame into a completely Yclosed position withconcurrent application of pressure to the'exterior surfaces of the halfrings B to maintain them in a closed, y'circle-defining position duringscrewing or unscrewingof a tubular member. The transmission T and lgearshift N provided in lthe present4 invention act positively to permiteasy change of the gear ratios between ring gear 41 and driving fgear117 withoutV recourse to the Vclutch mechanism disclosed in mypreviously mentioned Patent No. 2,846,909. Y Y y 'c .It ,will be obviousto those skilled in the art that various changes may bepmade in theinvention without departing fromthe spirit and scope thereof, andtherefore Vthe invention/is not limited by that which is shown in Ythedrawingganddescribed in the specification, but Vonly/as indicated in theappended claims.

lclaim: 1- a ,Y 1. A power-driven pipe tongL comprising: a frame member;Ia jaw member pivotallyrsecured to said frame member that cooperatestherewith to define a pipe-receiv- YingV opening; track means formed` onsaid ,members and encompassing said opening; a.pair of support halfrings rotatably mounted on said track means; two semi-circulardiecarriers rotatably mountedV on said half rings; a plurality ofcircumferentially spaced, radially movable die blocks mounted onV saiddie carriers; cam means'v disposed at fixedpositionsV relative to saidhalf `rings,yvhih cam meansA is slidably'engaged'by the exterior ends ofsaid die blocks when said die carriers are rotated in either of twopossible directions relative torsaid halfV ringsfwithY Vsaid die' blocksbeingrnoved inwardlyfwhensaid slidablemove- `ment `takes placejiuidV,actuated Ypower means;V `'variable speed Vtransmission Ymeansthatconnect saidY power means suddenly rotate said half rings so yas ltocause initial relai tive movement between said'lralf rings and said diecar'. riers, due tothe inertia ofthe latter, to the extent that beforerotating with said die carriers and half rings said blocks areiirstmoved inwardly to grip the exterior'surface ofV a pipe disposed in saidopening; fluid operated llatch meansfor releasably locking said frame'and' jaw members together; rst valve means; second Vvalve means; firstconduit means connectable to a source of 'tiuid under pressure andextending to said rst and second-valve means land thence to said powermeans and latch means, said first Valve means being adapted toselectively deliver said iiuid to said powernmeans in either of twopossible directions, to pennit rotation of said half ringsn'rdieV car-Yriers` and dies in either of two possiblep directions, said second valve'means being adapted to selectively deliver said uid to said latchingmeans to Vcauserthe same to assume either a latched or unlatchedposition, with the magnitude of the 'latching force holding 'said aw'and' frame members togethenbeing directly proportional to the intensityof the iluid pressure supplied thrQUgh .Said conduit to actuate saidpower means; and second conduit means capable of returningV fluid tosaid so'urcelduring actuation of said latching means. n v 2. Apower-driven pipetong `as Vderned in claim l wherein said latching meansincludes an 'engageable member rigidly axedto said frame member and anengaging member movably mounted on said jaw member, which engageableandY engaging members are capable of being placed in an 'engagingposition when the free ends of said 'iframe and jaw members are adjacentbut not inrabutting contact, a cylinder supported Yfrom-said jaw member,va piston slidably mounted inlsaid cylinder, 'a pistonrod lrigidlyconnected to said piston, movement-imparting means that transmits motionof said piston `rod to said engaging member to force said engaging andYengageable members to drawV said frame and jaw Vmembers together andplace said Vfree ends thereof in pressure abutment or permit saidengaging and engageable members to assume relative positions where saidfree ends are out of abutment and said engaging member can bedisengaged' fromsaid engageable member, and two tubular connectorsV onthe ends of said cylinder and communicatingY with the interior thereofconnected to said rst conduit means, with said second valve means beingcapableV of selectively delivering said fluid to either of saidconnectors to move said piston in a desired direction and lactuate saidmovement-impart.- ingrmea'nsl Y 3.'A power-driven pipe tongas defined inclaim 2 'wherein a plurality of rollersare provided that rotatably'tactwith said half 'rings ,when the Vfree ends of said frame and'Y jawmembers are in pressure abutment; ,A I Y 4. A` power-driven pipe tong asVdeined in cl` V3 wherein said transmission means comprise' twohalf ring'gears aixed to the exterior surfacesof said half rings, a n dn'vengearin engagement with saidV 'half ring gears, a

driving Vgear rotated by said power means, two'mo'vable gears diierentVin diameter, a gear shift for moving'said 'to saidv half rings torotate "the'rsame,V said transmission Y Y Y means being'capable ofpermittings'aid power means'to Vtwo gears, and aY plurality of gearscapable of transmitting rotational motion from said driving gear' tosaid'driven gear through either of said movable two' gears, with said'shift'when moved to dispose Ia tirst of said two gears in a 'rstposition causing said half ring gears/to be driven Vat high speed, lowYtorque, and said shift when moved to dis-V prose an second 'of saidV twogears a secondY position causing said half ring gears tofbe driven atlow speed,"'high torque.' Y u i..A` power-drivenY pipeV tong lasdenedrin claim '-1Y wherein` said latch-means includes anengageablemember rigidly axed to said frame member and an engagingmember movably mounted on said jaw member, a cylinder supported fromsaid jaw member, a piston 'slidably mounted in said cylinder, :a pistonrod rigidly connected to said piston, movement-imparting means thattransmits motion of said piston rod to said engaging member to move thesame into engagement with said engageable member and out of engagementtherewith, and two tubular connectors on the ends of said cylinder, withsaid second valve means being capable of selectively delivering saidfluid to either of said Connectors to move said piston and piston rod ina desired direction to engage or disengage said engaging member fromsaid engageable member.

6. A power-driven pipe tong as dened in claim wherein ra shaft isprovided; two parallel vertically spaced plates are rigidly aixed tosaid jaw member, with said plates having vertically aligned slots formedtherein in which the end portions of said shaft are rotatably andslidably mounted; a cam rigidly aixed to said shaft; a cam plate rigidlyaxed to said jaw member that is rotatably engageable by said cam, withsaid plate when so engaged by rotation of said cam in one directioncausing movement of said shaft away from said engageable member; an armrigidly ailixed to said shaft and pivotally connected to said pistonrod; and said engaging member comprising two parallel legs, the rst endsof which pivotally engage said shaft, a web that extends between thesecond ends of said legs and is rigidly connected thereto, with said webbeing adapted to be moved into engagement with said engageable member byrotation of said shaft in said one direction.

7. A power-driven pipe tong as dened in claim 6 wherein at least one setscrew is provided that is threadedly mounted in a tapped bore extendingthrough said web and normally disposed relative thereto, said screwhaving an end portion that projects into the space between said legs andengages said engageable member, which screw upon manual adjustmentthereof in said bore varies the length of said end portion to controlthe distance of travel of said piston in said cylinder before saidengaging member is placed in or moved out of engagement with saidengageable member.

8. A power-driven pipe tong as dened 4in claim 7 wherein a pivot supportis provided that pivotally supports said cylinder from said jaw member,and a handle is afxed to said web to permit placement of said engagingmember in a rst position from Where it can be subsequently moved toengage said engageable member prior to said frame and jaw membersassuming a closed position, and in any one of a number of secondpositions where said engaging member is out of engagement with saidengageable member, and said jaw and frame members can be pivoted to anopenposition.

9. A power-driven pipe tong, comprising: a hollow horizontally disposedframe member; a hollow horizontally disposed jaw member pivotallysecured to said frame member that cooperates therewith to dene apipe-receiving opening, said frame and jaw members having a plurality ofpairs of aligned circular openings formed in the upper and lowerportions thereof that are circumferentially spaced about saidpipe-receiving opening; a plurality of shafts; a plurality of rollersrotatably mounted on said shafts; a plurality of circular supports forsaid shaft, which supports are rotatably mounted in said circularopenings and eccentrically supports said shafts relatively to thelongitudinal axis of said pairs of aligned circular openings; indexingmeans that maintain each of said shaft supports at any one of aplurality of positions relative to the longitudinal axis of one of saidpairs of circular openings; a pair of support half rings rotatablymounted in said frame and jaw members and encompassing saidpipe-receiving opening, said half rings being `rotatably supported bysaid rollers, which upon adjustment of said indexing means are capableof pressure contacting said half rings with a desired compressive iforcewhen said frame and jaw members are closed; two semi-circular diecarriers rotatably mounted on said half rings; a plurality ofcircumferentially spaced, radially movable die blocks mounted on saiddie carriers; cam means disposed at fixed positions relative to saidhalf rings, which cam means are slidably engaged by the exterior ends ofsaid die blocks when said die carriers are rotated in either of twopossible directions relative to said half rings, with said die blocksbeing moved inwardly when said slidable movement takes place; fluidoperated latch means that force said frame and jaw members into a closedposition and so maintain the same untii the actuating pressure on saidfluid is released; power means; and variable speed transmission meansconnecting said power means to said half rings to rotate the same, saidtransmission means being capable of permitting said power means tosuddenly rotate said half rings so as to cause initial relative movementbetween said half rings and said die carriers, ldue to the inertia ofthe latter, to the extent that before rotating with said die carriersand half rings said blocks `are first moved inwardly to grip theexterior surface of a pipe disposed in said opening.

10. A power-driven pipe tong, comprising: a hollow horizontally disposedIframe member; a hollow horizontally disposed jaw member pivotallysecured to said frame member that cooperates therewith to define apipe-receiving opening, said frame and jaw members having a plurality ofpairs of aligned circular openings formed in the upper and lowerportions thereof circumferentially spaced about said pipe-receivingopening; `a plurality of shafts; a plurality of rollers rotatablymounted on said shafts, which supports are rotatably mounted in saidcircular openings and eccentrically support said shafts relative to thelongitudinal axis of said pairs of aligned openings; indexing means thatmaintain each of said shaft supports at any one of a plurality ofpositions relative to the longitudinal axis of one of said pairs ofcircular openings; a pair of support half rings rotatably mounted insaid frame and jaw members and encompassing said pipe-receiving opening,said half rings being rotatably supported by said rollers, which uponadjustment of said indexing means are capable of contacting said halfrings with a desired compressive force when said frame and jaw membersare closed; two semicircular die carriers rotatably mounted on said halfrings; a plurality of circumferentially spaced, radially movable dieblocks mounted on said die carriers; cam means disposed at fixedpositions relative to said half rings, which cam means is slidablyengaged by the eX- terior ends of said die blocks when said die carriersare rotated in either of two possible directions relative to said halfrings, with said die blocks being moved inwardly when said slidablemovement takes place; fluid actuated latch means for releasably lockingsaid frame and jaw members together; fluid actuated power means forrotating said half rings; and uid conducting means capable of supplyinguid under substantially the same pressure to both said latch means andsaid power means.

References Cited in the le of this patent UNITED STATES PATENTS2,618,468 Lundeen Nov. 18, 1952 2,650,070 Lundeen Aug. 25, 19532,703,221 Gardner Mar. 1, 1955 2,741,460 Gardner Apr. 10, 1956 2,780,950Province Feb. 12, 1957 2,846,909 Mason Aug. 12, 1958 2,862,690 MasonDec. 2, 1958

